The human foot daily encounters a variety of impact forces as a consequence of individual activity. Activities such as standing, walking, running, and jumping exert forces on an individual's feet that can cause soreness, fatigue, and injury.
Many different theories as to the optimum support and cushioning in a shoe design have been suggested in the past. The most common view however is that an average consumer will benefit from an appropriate amount of arch support, along with resiliency and cushioning in the shoe sole. A properly designed shoe will allow the consumer to be on their feet for long period of time without discomfort or pain.
A number of shoe designs providing shock absorption and/or resiliency have been proposed. These include soles containing springs, gels, or foams that store energy during compression and return energy during expansion. However, these solutions can increase weight or cost of the shoe and may have an unnatural feel.
Thus, there continues to be a need for a shoe sole construction that provides improved cushioning, energy return, and responsiveness throughout the life of the shoe.